Fuel transfer pump system

Abstract

A Fuel transfer pump system comprising a multi-mode control process for transferring fuel. The multi-mode control process comprising a closed loop pressure control mode for maintaining fuel pressure at an outlet of a fuel transfer pump at a substantially constant target pressure and having a soft start mode for bidirectionally ramping up to the target pressure by utilizing an open loop control in combination with the closed loop pressure control mode; a current control mode dynamically switchable from the closed loop pressure control mode for controlling a motor driving the fuel transfer pump as a function of a predetermined current threshold; a DC-bus voltage compensation mode operable with either the closed loop pressure control mode or the current control mode for compensating DC bus voltage sag; and an open loop ramp down mode for ramping open loop motor RPMs to zero from any other mode for shutting down system operation.

We claim: 
     
       1. A method for controlling a fuel transfer pump delivering fuel to a high pressure fuel injection pump; said method comprising:
 providing a fuel transfer pump having an inlet port which is connectable in fluid communication with a fuel source and an outlet port which is connectable in fluid communication with a high pressure fuel injection pump; 
 providing a motor for driving the fuel transfer pump for drawing fuel through the inlet port from the fuel source and pumping pressurized fuel out the outlet port; 
 measuring a fuel pressure at a location which is in fluid communication with the outlet port; 
 controlling an operating speed of the motor driving the fuel transfer pump as a function of the measured fuel pressure for defining a closed loop pressure control mode for controlling the measured fuel pressure to a target fuel pressure; 
 measuring a current utilized in operating the motor; 
 comparing the measured current to a predefined threshold current value; 
 correlating the measured current to at least one anomalous condition when indicated by the comparison step; and 
 switching from the closed loop pressure control mode for controlling the operating speed of the motor as a function of the measured fuel pressure to a current control mode for controlling the operating speed of the motor as a function of the measured current when the measured current is correlated by the correlation step to at least the one anomalous condition. 
 
     
     
       2. The method of  claim 1  wherein at least the one anomalous condition is indicative of an obstruction of the fluid communication between the outlet port of the fuel transfer pump and the high pressure fuel injection pump. 
     
     
       3. The method of claim I Wherein at least the one anomalous condition is indicative of a clogged filter which is connectable in fluid communication between the outlet port of the fuel transfer pump and the high pressure fuel injection pump. 
     
     
       4. A method for controlling a fuel transfer pump delivering fuel to a high pressure fuel injection pump; said method comprising:
 providing a fuel transfer pump having an inlet port which is connectable in fluid communication with a fuel source and an outlet port which is connectable in fluid communication with a high pressure fuel injection pump; 
 providing a motor for driving the fuel transfer pump for drawing fuel through the inlet port from the fuel source and pumping pressurized fuel out the outlet port; 
 measuring a fuel pressure at a location which is in fluid communication with the outlet port; 
 controlling an operating speed of the motor driving the fuel transfer pump as a function of the measured fuel pressure for defining a closed loop pressure control mode for controlling the measured fuel pressure to a target fuel pressure; 
 measuring a current utilized in operating the motor: 
 comparing the measured current to a predefined threshold current value; 
 correlating the measured current to at least one anomalous condition when indicated by the comparison step; 
 switchng from the closed loop pressure control mode for controlling the operating speed of the motor as a function of the measured fuel pressure to a current control mode for controlling the operating speed of the motor as a function of the measured current when the measured current is correlated by the correlation step to at least the one anomalous condition; and 
 cascading a DC voltage compensation control mode with the closed loop pressure control mode for defining a value of the target fuel pressure as a function of a DC voltage utilized in operating the motor for compensating for DC voltage fluctuations. 
 
     
     
       5. A method for controlling a fuel transfer pump delivering fuel to a high pressure fuel injection pump; said method comprising:
 providng a fuel transfer pump having an inlet port which is connectable in fluid communication with a fuel source and an outlet port which is connectable in fluid communication with a high pressure fuel injection pump; 
 providing a motor for driving the fuel transfer pump for drawing fuel through the inlet port from the fuel source and pumping pressurized fuel out the outlet port; 
 measuring a fuel pressure at a location which is in fluid communication with the outlet port; 
 controlling an operating speed of the motor driving the fuel transfer pump as a function of the measured fuel pressure for defining a closed loop pressure control mode for controlling the measured fuel pressure to a target fuel pressure; 
 measuring a current utilized in operating the motor; 
 comparing the measured current to a predefined threshold current value; 
 correlating the measured current to at least one anomalous condition when indicated by the comparison step; 
 switching from the closed loop pressure control mode for controlling the operating speed of the motor as a function of the measured fuel pressure to a current control mode for controlling the operating speed of the motor as a function of the measured current when the measured current is correlated by the correlation step to at least the one anomalous condition; and 
 cascading a soft start mode with the closed loop pressure control mode for ramping up the current utilized in operating the motor when the current is below a predefined current limit and ramping down the current utilized in operating the motor when the current is above the predefined current limit until the target fuel pressure is substantially obtained. 
 
     
     
       6. The method of  claim 5  further including a step of cascading a DC voltage compensation control mode with the soft start mode for defining a value of the target fuel pressure as a function of a DC voltage utilized in operating the motor for compensating for DC voltage fluctuations. 
     
     
       7. A method for controlling a fuel transfer pump delivering fuel to a high pressure fuel injection pump; said method comprising:
 providing a fuel transfer pump having an inlet port which is connectable in fluid communication with a fuel source and an outlet port which is connectable in fluid communication with a high pressure fuel injection pump; 
 providing a motor for driving the fuel transfer pump for drawing fuel through the inlet port from the fuel source and pumping pressurized fuel out the outlet port; 
 measuring a fuel pressure which is in fluid communication with the outlet port; 
 controlling an operating speed of the motor driving the fuel transfer pump as a function of the measured fuel pressure for defining a closed loop pressure control mode for controlling the measured fuel pressure to a target fuel pressure; 
 measuring a current utilized in operating the motor; 
 comparing the measured current to a predefined threshold current value; 
 correlating the measured current to at least one anomalous condition when indicated by the comparison step; 
 switching from the closed loop pressure control mode for controlling the operating speed of the motor as a function of the measure fuel pressure to a current control mode for controlling the operating speed of the motor as a function of the measured current when the measured current is correlated by the correlation step to at least the one anomalous condition; and 
 controlling the operating speed of the motor driving the fuel transfer pump under the closed loop pressure control mode for a predetermined amount of time when a measured fuel temperature is above a predetermined threshold value and further including a step of remeasuring the fuel temperature after the predetermined amount of time and continuing the step of controlling the operating speed of the motor driving the fuel transfer pump under the closed loop pressure control mode if the remeasured fuel temperature falls below the predetermined threshold value or further including a step of ramping down the motor to an off state if the remeasured fuel temperature remains above the predetermined threshold value. 
 
     
     
       8. A method for minimizing current inrush to a fuel transfer pump upon initial start up; said method comprising:
 providing a fuel transfer pump having an inlet port which is connectable in fluid communication with a fuel source and an outlet port which is connectable in fluid communication with a high pressure fuel injection pump; 
 providing a motor for driving the fuel transfer pump for drawing fuel through the inlet port from the fuel source and pumping pressurized fuel out the outlet port; 
 measuring a fuel pressure at a location which is in fluid communication with the outlet port; 
 controlling an operating speed of the motor driving the fuel transfer pump as a function of the measured fuel pressure and a moving fuel pressure; 
 measuring a current utilized in operating the motor; 
 comparing the measured current to a predefined threshold current value; and 
 utilizing a soft start mode for ramping up the current utilized in operating the motor when the measured current is below the predefined threshold current value as indicated by the comparison step and ramping down the current utilized in operating the motor when the current is above the predefined threshold current value as indicated by the comparison step for providing the moving fuel pressure until the moving fuel pressure reaches a target fuel pressure. 
 
     
     
       9. A fuel transfer pump system for delivering fuel to a high pressure pump of a fuel injection system, said fuel transfer pump system comprising:
 a fuel transfer pump having an inlet port which is connectable in fluid communication with a source of fuel and an outlet port which is connectable in fluid communication with a high pressure fuel injection pump; 
 a motor for driving said fuel transfer pump for drawing fuel through said inlet port from said fuel source and pumping pressurized fuel out said outlet port at a target fuel pressure; 
 means for measuring fuel pressure at a location in fluid communication with said outlet port of said fuel transfer pump; 
 means for measuring current utilized in operating said motor; and 
 a controller operatively coupled to said motor and connected in signal communication with said fuel pressure measuring means and said current measuring means, said controller being configured to adaptively switch between a closed loop pressure control mode for controlling an operating speed of said motor for obtaining said target fuel pressure as a function of said measured fuel pressure to a current control mode for controlling said operating speed of said motor as a function of said measured current when said measured current is correlated to at least one anomalous condition based on a comparison between said measured current and a predefined threshold current value. 
 
     
     
       10. The system of  claim 9  wherein at least said one anomalous condition is indicative of an obstruction of the fluid communication between said outlet port of said fuel transfer pump and said high pressure fuel injection pump. 
     
     
       11. The system of  claim 9  wherein at least said one anomalous condition is indicative of a clogged filter which is connectable in fluid communication between said outlet port of said fuel transfer pump and said high pressure fuel injection pump. 
     
     
       12. A fuel transfer pump system for delivering fuel to a high pressure pump of a fuel injection system, said fuel transfer pump system comprising:
 a fuel transfer pump having an inlet port which is connectable in fluid communication with a source of fuel and an outlet port which is connectable in fluid communication with a high pressure fuel injection pump; 
 a motor for driving said fuel transfer pump for drawing fuel through said inlet port from said fuel source and pumping pressurized fuel out said outlet port at a target fuel pressure; 
 means for measuring fuel pressure at a location in fluid communication with said outlet port of said fuel transfe pump; 
 means for measuring current utilized in operating said motor; and 
 a controller operatively coupled to said motor and connected in signal communication with said fuel pressure measuring means and said current measuring means, said controller being configured to adaptively switch between a closed loop pressure control mode for controlling an operating speed of said motor for obtaining said target fuel pressure as a function of said measured fuel pressure to a current control mode for controlling said operating speed of said motor as a function of said measured current when said measured current is correlated to at least one anomalous condition based on a comparison between said measured current and a predefined threshold current value; and 
 said controller being further configured to cascade a DC voltage compensation control mode with said closed loop pressure control mode for defining a value of said target fuel pressure as a function of a measured DC voltage utilized in operating said motor for compensating for DC voltage fluctuations. 
 
     
     
       13. A fuel transfer pump system for delivering fuel to a high pressure pump of a fuel injection system, said fuel transfer pump system comprising:
 a fuel transfer pump having an inlet port which is connectable in fluid communication with a source of fuel and an outlet port which is connectable in fluid communication with a high pressure fuel injection pump; 
 a motor for driving said fuel transfer pump for drawing fuel through said inlet port from said fuel source and pumping pressurized fuel out said outlet port at a target fuel pressure; 
 means for measuring fuel pressure at a location in fluid communication with outlet port of said fuel transfer pump; 
 means for measuring current utilized in operating said motor; and 
 a controller operatively coupled to said motor and connected in signal communication with fuel pressure measuring means and said current measuring means, said controller being configured to adaptively switch between a closed loop pressure control mode for controlling an operating speed of said motor for obtaining said target fuel pressure as a function of said measured fuel pressure to a current control mode for controlling said operating speed of said motor as a function of said measured current when said measured current is correlated to at least one anomalous condition based on a comparison between said measured current and a predefined threshold current value; and 
 said controller being further configured to cascade a soft start mode with said closed loop pressure control mode for ramping up said current utilized in operating said motor when said current is below a predefined current limit and ramping down said current utilized in operating said motor when said current is above said predefined current limit until said target fuel pressure is substantially obtained. 
 
     
     
       14. The system of  claim 13  wherein said controller being further configured to cascade a DC voltage compensation control mode with said soft start mode for defining a value of said target fuel pressure as a function of a DC voltage utilized in operating said motor for compensating for DC voltage fluctuations. 
     
     
       15. A fuel transfer pump system for delivering fuel to a high pressure pump of a fuel injection system, said fuel transfer pump system comprising:
 a fuel transfer pump having an inlet port which is connectable in fluid communication with a source of fuel and an outlet port which is connectable in fluid communication with a high pressure fuel injection pump; 
 a motor for driving said fuel transfer pump for drawing fuel through said inlet port from said fuel source and pumping pressurized fuel out said outlet port at a target fuel pressure; 
 means for measuring fuel pressure at a location in fluid communication with said outlet port of said fuel transfer pump; 
 means for measuring current utilized in operating said motor; and 
 a controller operatively coupled to said motor and connected in signal communication with said fuel pressure measuring means and said current measuring means, said controller being configured to adaptively switch between a closed loop pressure control mode for controlling an operating speed of said motor for obtaining said target fuel pressure as a function of said measured fuel pressure to a current control mode for controlling said operating speed of said motor as a function of said measured current when said measured current is correlated to at least one anomalous condition based on a comparison between said measured current and a predefined threshold current value, and 
 said controller being further configured to control said operating speed of said motor driving said fuel transfer pump under said closed loop pressure control mode for a predetermined amount of time when a measured fuel temperature is above a predetermined threshold value and further configured to remeasure said fuel temperature after said predetermined amount of time and to control said operating speed of said motor driving said fuel transfer pump under said closed loop pressure control mode if said remeasured fuel temperature falls below said predetermined threshold value and said controller being further configured to ramp down said motor to an off state if said remeasured fuel temperature remains above said predetermined threshold value. 
 
     
     
       16. A non-transitory microcontroller-readable memory containing microcontroller-executable instructions that, when executed by a processor, cause the processor to perform a multi-mode control method of a motor driving a pump, said method comprising:
 controlling an operating speed of a motor driving a pump for pressurizing fluid as a function of a measured pressure of the pressurized fluid for defining a closed loop pressure control mode for obtaining a target fluid pressure; and 
 switching from the closed loop pressure control mode to a current control mode for controlling the operating speed of the motor as a function of a measured current utilized in operating the motor when the measured current is indicative of at least one anomalous condition. 
 
     
     
       17. A non-transitory microcontroller-readable memory containing microcontroller-executable instructions that, when executed by a processor, cause the processor to perform a multi-mode control method of a motor driving a pump, said method comprising:
 controlling an operating weed of a motor driving a pump for pressurizing fluid as a function of a measured pressure of the pressurized fluid for defining a closed loop pressure control mode for obtainin a target fluid pressure; and 
 switching from the closed loop pressure control mode to a current control mode for controlling the operating speed of the motor as a function of a measured current utilized in operating the motor when the measured current is indicative of at least one anomalous condition; and 
 cascading a DC voltage compensation control mode with the closed loop pressure control mode for defining a value of the target fluid pressure as a function of a DC voltage utilized in operating the motor for compensating for DC voltage fluctuations, 
 
     
     
       18. A non-transitory microcontroller-readable memory containing microcontroller-executable instructions that, when executed by a processor, cause the processor to perform a multi-mode control method of a motor driving a pump, said method comprising:
 controlling an operating speed of a motor driving a pump for pressurizing fluid as a function of a measured pressure of the pressurized fluid for defining a closed loop pressure control mode for obtaining a target fluid pressure; and 
 switching from the closed loop pressure control mode to a current control mode for controlling the operating speed of the motor as a function of a measured current utilized in operating the motor when the measured current is indicative of at least one anomalous condition; and 
 cascading a soft start mode with the closed loop pressure control mode for ramping up a current utilized in operating the motor when the current is below a predefined current limit and ramping down the current utilized in operating the motor when the current is above the predefined current limit until the target fluid pressure is substantially obtained. 
 
     
     
       19. The non-transitory microcontroller-readable memory of  claim 18  further comprising a step of cascading a DC voltage compensation control mode with the soft start mode for defining a value of the target fluid pressure as a function of a DC voltage utilized in operating the motor for compensating for DC voltage fluctuations. 
     
     
       20. A non-transitory microcontroller-readable memory containing microcontroller-executable instructions that, when executed by a processor, cause the processor to perform a multi-mode control method of a motor driving a pump, said method comprising:
 controlling an operating speed of a motor driving a pump for pressurizing fluid as a function of a measured pressure of the pressurized fluid for defining a closed loop pressure control mode for obtaining a target fluid pressure; and 
 switching from the closed loop pressure control mode to a current control mode for controlling the operating speed of the motor as a function of a measured current utilized in operating the motor when the measured current is indicative of at least one anomalous condition; and 
 controlling the operating speed of the motor driving the pump under the closed loop pressure control mode for a predetermined amount of time when a measured fluid temperature is above a predetermined threshold value and further including a step of remeasuring the fluid temperature after the predetermined amount of time and continuing the step of controlling the operating speed of the motor driving the pump under the closed loop pressure control mode if the remeasured fluid temperature falls below the predetermined threshold value or further including a step of ramping down the motor to an off state if the remeasured fluid temperature remains above the predetermined threshold value.